Three people are now dead after lightning struck outside the White House on Thursday evening.
The third victim was pronounced dead Friday evening, following the deaths yesterday of a husband and wife from Wisconsin who had been celebrating more than five decades of marriage in the U.S. capital.
A fourth person remains hospitalized with life-threatening injuries.
James Mueller, 76, and Donna Mueller, 75, of Janesville, Wis., died of their injuries after the lightning strike in Lafayette Park, located directly outside the White House complex, the Metropolitan Police Department said Friday.
The third victim, a 29-year-old man, was pronounced dead Friday. The fourth person, a woman, was in critical condition, the police department said. Their identities were not immediately released.
Authorities did not reveal how the people were injured, other than to say they were critically hurt in the lightning strike.
'Very loving couple'
The Muellers were on a trip to Washington to celebrate their 56th wedding anniversary, according to their niece, Michelle McNett, of Janesville.
"They were a very loving couple," McNett told the Wisconsin State Journal. "They were very, very family oriented. I think everyone's just in shock right now and kind of request privacy."
The couple had five children, 10 grandchildren and four great-grandchildren, McNett told the paper.
Donna was a teacher and in retirement worked at the Comfort Shoppe, a local furniture store. James was a retired contractor who had his own drywall business.
McNett said she's not sure why the couple picked the nation's capital for their vacation, but added that Donna "was a constant learner."
She said they loved having gatherings and had just hosted a big family event a couple of weeks ago.
"They were very religious," she said. "Just the kind of people who would give the shirt off their back to do anything for you, both of them."
Secret Service, police rendered first aid
Officers with the Secret Service and the U.S. Park Police witnessed the lightning strike and ran over to render first aid, officials said.
Emergency medical crews were called to the scene just before 7 p.m. ET and took all of the victims to hospital.
"We are saddened by the tragic loss of life after the lightning strike in Lafayette Park," said White House press secretary Karine Jean-Pierre. "Our hearts are with the families who lost loved ones, and we are praying for those still fighting for their lives."